python - How can I draw half circle in OpenCV? -

how can draw half circle in opencv below?

if not, how can in python?

here's 2 ways how half circle cv2 using python. both examples complete , runnable example scripts

first easier example: creating half circle mentioned rounded corners

import cv2 import numpy np  # colors (b, g, r) white = (255, 255, 255) black = (0, 0, 0)   def create_blank(width, height, color=(0, 0, 0)):     """create new image(numpy array) filled color in bgr"""     image = np.zeros((height, width, 3), np.uint8)     # fill image color     image[:] = color      return image   def draw_half_circle_rounded(image):     height, width = image.shape[0:2]     # ellipse parameters     radius = 100     center = (width / 2, height - 25)     axes = (radius, radius)     angle = 0     startangle = 180     endangle = 360     thickness = 10      # http://docs.opencv.org/modules/core/doc/drawing_functions.html#ellipse     cv2.ellipse(image, center, axes, angle, startangle, endangle, black, thickness)   # create new blank 300x150 white image width, height = 300, 150 image = create_blank(width, height, color=white) draw_half_circle_rounded(image) cv2.imwrite('half_circle_rounded.jpg', image) 

result:

second example: creating half circle without rounded corners

import cv2 import numpy np  # colors (b, g, r) white = (255, 255, 255) black = (0, 0, 0)   def create_blank(width, height, color=(0, 0, 0)):     """create new image(numpy array) filled color in bgr"""     image = np.zeros((height, width, 3), np.uint8)     # fill image color     image[:] = color      return image   def draw_half_circle_no_round(image):     height, width = image.shape[0:2]     # ellipse parameters     radius = 100     center = (width / 2, height - 25)     axes = (radius, radius)     angle = 0     startangle = 180     endangle = 360     # when thickness == -1 -> fill shape     thickness = -1      # draw black half circle     cv2.ellipse(image, center, axes, angle, startangle, endangle, black, thickness)      axes = (radius - 10, radius - 10)     # draw bit smaller white half circle     cv2.ellipse(image, center, axes, angle, startangle, endangle, white, thickness)   # create new blank 300x150 white image width, height = 300, 150  image = create_blank(width, height, color=white) draw_half_circle_no_round(image) cv2.imwrite('half_circle_no_round.jpg', image) 

result: